1. Field of the Invention
The present invention relates to a confidential information management system suitable for use in storing and managing various types of information (confidential information: ID numbers, passwords, encryption keys, digital certificates, etc.) to be used in user verification. The present invention also relates to information terminals employed in the present system for downloading such confidential information thereto.
2. Description of the Related Art
User verification (to confirm an object user of a system or an application is an authorized user) has recently been carried out by using confidential information, such as personal identification codes and passwords (hereinafter will be also called “password verification”). In this method, the confidential information input by the object user is compared with that registered previously. If the two are then decided to be identical, the object user is verified. This method provides a handy, user-friendly verification, and thus is the most common method of user verification in today's system infrastructure.
Multifunctional mobile information terminals {various types of potable information terminals such as PDAs (personal digital assistants) and mobile telephones} nowadays not only function as electronic notepads or telephones but also receive/transmit electronic information and image information via wired/wireless networks. Further, such mobile information terminals can also be used in bank account settlement, electronic commerce, or securities trading. For realizing these varying functions in one mobile information terminal, various types of applications are started or executed on the mobile information terminal.
When such applications are started or executed on the mobile information terminal, an ID and a password must be input for each application. Likewise, when bank account settlement or electronic commerce transaction is performed, a bank account number and a personal identification code must be input. In general, such an ID and a bank account number are previously stored in a memory or the like so that it is unnecessary for the user to input such numbers by himself/herself, while the confidential information (password and personal identification code) for use in user verification must be input by the user with push or touch buttons (ten keys).
Accordingly, the user must remember plural passwords or personal identification codes, one for each application or system (bank, etc.). In cases where a variety of passwords and personal identification codes are used, the following problems (a) through (d) are encountered.
(a) Many of users tend to use an easy-to-remember string of characters or digits as a password or a PIN; for example, the user's or family member's name or birthday, telephone number, favorite word, etc. Assuming that an information terminal with such passwords or personal identification codes registered is stolen or lost, there is a danger that an unauthorized person might use the bank account settlement or electronic commerce function equipped in the terminal.
(b) Using passwords or personal identification codes in user verification makes the system simple with reduced manufacturing cost, but it is necessary for the user to be security-conscious. Otherwise if hard-to-remember passwords or personal identification codes are used in an effort to increase the security, the user might forget them. If the passwords or personal identification codes are stored in the information terminal for the user's convenience, they can be easily read by unauthorized persons because of the poor security so that the unauthorized person can use the above-mentioned functions of the terminal.
(c) A single-sign-on system or LDAP (lightweight directory access protocol), in which a single password is used to log-in to plural systems collectively, is rendered poor in security, because an unauthorized person may access all the relevant systems merely by inputting the one single password.
(d) Since the single-sign-on system is based on the premise that each of the relevant systems is associated with one another, it is difficult to support all systems by a single-sign-on system.
In the meantime, in addition to the above-mentioned confidential information, the user's property (ID card, etc.) and the user's biometric information (fingerprint, palmprint, finger shape, hand shape, voiceprint, retina, iris, facial recognition, signature dynamics, blood vessel pattern, key strokes, etc.), unique to the user, are also used in verifying the user.
The former is disadvantageous in that user verification cannot be performed if the user forgets to carry the property (ID card, etc.) on him/her. Further, since an unauthorized person can also use the property, the security level is low.
The latter is disadvantageous not only in that all users cannot employ the method, but also in that plural IDs must be remembered, one for each system, thereby necessitating troublesome management of those IDs for the user. Moreover, in order to employ this method, it is necessary to make significant changes to existing user verification infrastructures which are adapted to the currently popular types of password verification.
In view of these, it has been hoped that an effective and secure use of the conventional password verification is accomplished, without employing such as a single-sign-on system, nor making any changes to the existing user verification infrastructures.